Even the poorest countries TFR are declining, especially African countries which has the highest TFR https://www.economist.com/middle-east-and-africa/2023/04/05/the-worlds-peak-population-may-be-smaller-than-expected

The article just talked about how increasing social spending and work flexibility increase fertility rates to those who benefit, while those who don’t benefit saw a decline in TFR

The author may be down for that considering he also writes on YIMBY stuff